Inference of interactions in cyanobacterial-heterotrophic co-cultures via transcriptome sequencing
Inference of interactions in cyanobacterial-heterotrophic co-cultures via transcriptome sequencing
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DOI：
10.1038/ismej.2014.69
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发表时间：
2014-11-01
期刊：
影响因子：
11
通讯作者：
Konopka, Allan
中科院分区：
文献类型：
--
作者：
Beliaev, Alexander S.;Romine, Margie F.;Konopka, Allan
我们使用深度测序技术来鉴定广盐性单细胞蓝藻聚球藻7002和海洋兼性需氧菌腐败希瓦氏菌W3-18-1在共培养物中生长的转录适应，并推断碳通量分布对光合自养-异养相互作用的影响。两种生物体对共培养的总体转录组响应由其各自的生理学和生长限制形成。碳限制导致代谢能力的扩大，这通过转运和分解代谢途径的转录上调来表现。虽然生长耦合发生通过乳酸氧化或光合固定碳的分泌，有证据表明，这两种生物体之间的特定代谢相互作用。这些假设的相互作用是从特定氨基酸（例如，丙氨酸和甲硫氨酸）的蓝细菌，这与希瓦氏菌W3-18-1中相应的生物合成机制的下调相关的排泄推断的。此外，在共培养过程中，许多Fe调节的聚球藻7002基因的mRNA水平的广泛和一致的降低可能表明铁的可用性增加，以及更容易和能量有效的机制，由蓝藻铁收购。此外，有证据表明，在潜在的新的相互作用的产氧光合自养和异养相关的氧化应激反应的转录模式表明，聚球藻7002，而不是希瓦氏菌W3-18-1提供清除功能的活性氧在共培养条件下。这项研究提供了一个初步的了解光合自养-异养相互作用的复杂性，并带来了新的观点，他们的作用的鲁棒性和稳定性的协会。
We used deep sequencing technology to identify transcriptional adaptation of the euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 and the marine facultative aerobe Shewanella putrefaciens W3-18-1 to growth in a co-culture and infer the effect of carbon flux distributions on photoautotroph-heterotroph interactions. The overall transcriptome response of both organisms to co-cultivation was shaped by their respective physiologies and growth constraints. Carbon limitation resulted in the expansion of metabolic capacities, which was manifested through the transcriptional upregulation of transport and catabolic pathways. Although growth coupling occurred via lactate oxidation or secretion of photosynthetically fixed carbon, there was evidence of specific metabolic interactions between the two organisms. These hypothesized interactions were inferred from the excretion of specific amino acids (for example, alanine and methionine) by the cyanobacterium, which correlated with the downregulation of the corresponding biosynthetic machinery in Shewanella W3-18-1. In addition, the broad and consistent decrease of mRNA levels for many Fe-regulated Synechococcus 7002 genes during co-cultivation may indicate increased Fe availability as well as more facile and energy-efficient mechanisms for Fe acquisition by the cyanobacterium. Furthermore, evidence pointed at potentially novel interactions between oxygenic photoautotrophs and heterotrophs related to the oxidative stress response as transcriptional patterns suggested that Synechococcus 7002 rather than Shewanella W3-18-1 provided scavenging functions for reactive oxygen species under co-culture conditions. This study provides an initial insight into the complexity of photoautotrophic-heterotrophic interactions and brings new perspectives of their role in the robustness and stability of the association.